docs: def _parse_fields(self, query):
          """
          Parse the querystring args for fields.
  
          :param query: Dict of query args
          """
          field_args = {
              k: v
              for k, v in query.items() if k.startswith('fields[')
          }
  
          fields = {}
  
          for k, v in field_args.items():
              fields[k[7:-1]] = v.split(',')
  
          return fields